Inground, vinyl-lined, swimming pools require a hanger that is placed on the top of the steel panel, to connect the vinyl liner into. Almost every swimming pool has a deck, of some material, around it. This deck is most commonly poured concrete. Traditionally, this transition point would be made of aluminum or PVC (this is commonly called “coping”). Pool forms are typically made of Styrofoam, as has been the case for over a decade. The Styrofoam forms are disposed of after each installation.